components/sync/driver/model_associator.h

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_SYNC_DRIVER_MODEL_ASSOCIATOR_H_
#define COMPONENTS_SYNC_DRIVER_MODEL_ASSOCIATOR_H_

#include <stdint.h>

#include "base/synchronization/lock.h"
#include "components/sync/base/model_type.h"
#include "components/sync/model/sync_error.h"

namespace syncer {

class SyncMergeResult;

// This represents the fundamental operations used for model association that
// are common to all ModelAssociators and do not depend on types of the models
// being associated.
class AssociatorInterface {
 public:
  virtual ~AssociatorInterface() {}

  // Iterates through both the sync and the chrome model looking for
  // matched pairs of items. After successful completion, the models
  // should be identical and corresponding. Returns true on
  // success. On failure of this step, we should abort the sync
  // operation and report an error to the user.
  virtual SyncError AssociateModels(SyncMergeResult* local_merge_result,
                                    SyncMergeResult* syncer_merge_result) = 0;

  // Clears all the associations between the chrome and sync models.
  virtual SyncError DisassociateModels() = 0;

  // The has_nodes out parameter is set to true if the sync model has
  // nodes other than the permanent tagged nodes.  The method may
  // return false if an error occurred.
  virtual bool SyncModelHasUserCreatedNodes(bool* has_nodes) = 0;

  // Calling this method while AssociateModels() is in progress will
  // cause the method to exit early with a "false" return value.  This
  // is useful for aborting model associations for shutdown.  This
  // method is only implemented for model associators that are invoked
  // off the main thread.
  virtual void AbortAssociation() = 0;

  // Returns whether the datatype is ready for encryption/decryption if the
  // sync service requires it.
  // TODO(zea): This should be implemented automatically for each datatype, see
  // http://crbug.com/76232.
  virtual bool CryptoReadyIfNecessary() = 0;
};

}  // namespace syncer

#endif  // COMPONENTS_SYNC_DRIVER_MODEL_ASSOCIATOR_H_